Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Claystone is a fine-grained, dark gray to pink sedimentary rock which mainly consists of compacted and hardened clay
Discoverer
Unknown
Unknown
Etymology
From French, Latin lignum wood + -ite1
From English clay and stone as the rock contains more amount of clay
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Clastic
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Blue, Brown, Green, Grey, Orange, Red, White, Yellow
Durability
Durable
Durable
Appearance
Veined or Pebbled
Rough and Dull
Interior Uses
-
Decorative Aggregates, Entryways, Floor Tiles, Homes, Interior Decoration
Exterior Uses
-
As Facing Stone, Roof Tiles
Other Architectural Uses
-
Curbing
Construction Industry
for Road Aggregate, Steel Production
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
-
Artifacts, Sculpture, Small Figurines
Commercial Uses
Electricity Generation
Pottery
Types
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Claystone
Features
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Available in Lots of Colors and Patterns, Smooth to touch, Very fine grained rock
Archaeological Significance
Formation
Coal formation takes place due to accumulation of plant debris in a swamp environment. The Coal formation process continues, as peat turns into lignite brown or black coal at increasing heat and pressure.
Claystone is generally quite soft, but can be hard and brittle. It forms due to weathering of mudstone.
Mineral Content
-
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Aluminium Oxide, Ca, NaCl, CaO, Iron(III) Oxide, MgO, Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Water Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Porosity
Highly Porous
Very Less Porous
Luster
Dull to Vitreous to Submetallic
Dull
Specific Gravity
1.1-1.4
0
Transparency
Opaque
Opaque
Density
800-801 g/cm3
2-2.9 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Bangladesh, China, India, Russia
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, Panama, USA
South America
Brazil, Chile, Colombia, Venezuela
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
New South Wales, New Zealand, Queensland, Victoria, Western Australia